This is a pretty simple tool that allows you to push docker images to serverless-registry when the layers are too big.

bun install

Then:

docker tag my-image:latest $IMAGE_URI
echo $PASSWORD | USERNAME_REGISTRY=<your-configured-username> bun run index.ts $IMAGE_URI

It exports the image using docker save, then pushes each layer to the registry. It only supports Basic authentication as it's the one that serverless-registry uses.

It's able to chunk layers depending on the header oci-chunk-max-length returned by the registry when the client creates an upload.

• Every *.tar in the push folder is the exported image from docker, which is extracted into .cache.
• Then it's compressed to gzip and saved into .cache. Files that end in -ptr have a digest in the content that refers to another layer in the folder.

There is a few more workarounds in the code like having to use node-fetch as Bun overrides the Content-Length header from the caller.

This pushing tool is just a workaround on the Worker limitation in request body.

To push to a localhost registry you need to set the environment variable INSECURE_HTTP_PUSH=true.

If the reader is interested, there is more options or alternatives to have a faster pushing chunk tool:

1. We could redesign this tool to run with the Docker overlay storage. The biggest con is having to run a privileged docker container that uses https://github.com/justincormack/nsenter1 to access the Docker storage.

2. Create a localhost proxy that understands V2 registry protocol, and chunks things accordingly. The con is that docker has issues pushing to localhost registries.

3. Use podman like described in this very informative Github comment.

1. Use zstd instead.
2. Have a better unit test suite.